NAHA, Okinawa — In World War II’s waning days, 21-year-old Jo Oka, a Japanese Imperial Army soldier, was wounded and lying in a cot in the dark cave that served as an Imperial Japanese Army field hospital in Haebaru, in southern Okinawa.

The cave hospital was filled with more than 2,000 seriously wounded soldiers. No treatment was given to them. Instead, they were given poison.

Much has been told of the atrocities that took place in that cave, where wounded soldiers were disposed of by cyanide in the last stages of the Battle of Okinawa, as the devastated Imperial Army retreated farther south.

Until recently, however, the massacre was thought to have left no one alive. Even today, Oka believes he is the only survivor among soldiers who were given cyanide-laced milk by their own army.

Conscripted in January 1944 in his hometown of Kyoto, Oka was sent to China after two weeks of training. In August, his unit was reorganized and sent to Okinawa. In April 1945, the battle for Okinawa began.

Oka was a gunner with the Ishi Battalion; his unit was positioned on the front lines in Maeda in Urasoe.

“We were able to see Americans about 300 meters ahead,” he said. “It was the morning of April 28 in 1945.

“I was hiding in a trench with my sergeant, watching the movement of the enemy. When we found enemy troops near us, we fired at them, but then the return fire was tremendous.”

A trench mortar shell burst nearby. Shrapnel tore into Oka.

“My sergeant put me on his shoulder and carried me to a hospital in Shuri, where they removed a piece of shrapnel from my body,” he said.

Two days later, he was sent to a field hospital in Haebaru packed with wounded soldiers, he said. “The chamber I was put in was about 50 meters long. I was laid in the farthest row from the entrance and the closest to the exit.

“I don’t remember what I ate or if I ate at all because of the pain from my wound. Around May 23, everyone who could walk left the cave together with student nurses.”

Only the seriously injured and some medics remained. Food had never been plentiful — a small rice ball once a day. But eventually, the feedings stopped completely. No food or water was given for three days.

“We were simply abandoned there,” Oka said.

On the fourth day, a voice echoed in the cave, telling them that milk would be distributed.

“The murmur of excitement rose among nearly starving soldiers,” he said. “Everyone was overjoyed with long-awaited food, and I was excited, too.”

Patients in the rows near the entrance received the milk first.

“Shortly after, I heard some noises among patients near the entrance, but I thought that they were just carried away by the milk treat,” he said. “Soon, they all became quiet, so I thought they all went to sleep satisfied with the milk.”

His turn came. He first dipped his finger in the milk and licked it.

It was bitter.

Then, he remembers a block of brown sugar a student nurse had given him on the way to the cave hospital. “She handed it to me while I was on a stretcher, telling me that it would do me good at some time,” he said.

He added some of the sugar to the milk and tasted it, but it was still bitter. He added some more and tasted it. Even though moaning sounds drew closer, and he thought the milk was strange, he said, “I drank it anyway because I was very thirsty.” But soon, “I felt dizzy and a sharp pain ran through my stomach.”

He recalls shouting, “This is poison! We are being poisoned!” Immediately, he stuck a finger in his mouth to induce vomiting.

“I guzzled water in a canteen and vomited, at the same time handing the canteen to the solider next to me, urging him to do the same,” he said. “We repeated it again and again until all the water in the canteen was gone.”

Soon, the entire cave became quiet. They heard no more moans.

“I could finally understand what was going on,” Oka said. He realized they would be killed if they remained. “The next moment, the soldier next to me and I jumped off our cots and started to run away from the cave.”

That soldier soon was killed by U.S. fire. Oka escaped and wandered the front lines in Mabuni, Okinawa’s southernmost point, for about a month before being captured and made a prisoner of war June 28.

For 46 years, he remained silent about surviving the death cave. Only after a September 1991 story about the poisoning appeared in the Asahi Shimbun newspaper did Oka decide to talk about his experience.

Judging by the angry phone calls he received after his story was published in the newspaper, he said, many readers wished he hadn’t. Many found it hard to accept that their military committed such an atrocity to its own soldiers, he said.

“I can understand that because I could not believe it either,” he said. “But it was what actually happened and a part of history that cannot be denied.

“I come back to Okinawa every year to see my comrades and to console their spirits.”

There is one more thing he never fails to do on his annual visit: He buys blocks of brown sugar to take home.

Blackman, currently the Marine Corps Forces Central deputy commander at MacDill Air Force Base, Fla., also has been nominated for his third star.

Gregson was selected earlier this year to be Commander, Marine Forces Pacific, which oversees all Marines in Japan, Hawaii and California. He will replace Marine Lt. Gen. Earl B. Hailston, who is retiring.

Blackman, commissioned after graduating from Cornell University in 1970, was a platoon commander and company executive officer with 1st Battalion, 4th Marines. He also was a series commander at Marine Corps Recruit Depot San Diego, directed Sea School and was a company commander in 3rd Battalion, 1st Marines. He was executive officer for 8th Marines in 1987.

In 1988, he assumed command of 3rd Battalion, 8th Marines. In 1991, he was the U.S. Central Command’s commander-in-chief’s executive officer. In 1993, he commanded the 15th Marine Expeditionary Unit. In 1998, he was 2nd Marine Division’s assistant division commander and commanded the division from 1999 until 2001.

He has held numerous staff billets, including tours as a fellow in National Security Affairs at the Kennedy School of Government, military assistant to the secretary of the Navy and president of the Marine Corps University.